1. Field of the Invention
The present invention relates to substituted aminomethylenebis(phosphonic acid) derivatives or pharmaceutically acceptable salts thereof which are useful as medicines having a bone resorption inhibitory effect as well as an anti-inflammatory effect, an antirheumatic effect or the like.
2. Description of the related art
Substituted aminomethylenebis(phosphonic acid) derivatives having a heterocyclic ring are disclosed in Japanese patent laid-open No. 89,293/1980. The compounds disclosed in this Japanese patent gazette have an isoxazolyl group or a pyrazolyl group as the heterocyclic ring. The Japanese patent gazette mentions that these compounds can be used as agricultural chemicals, especially as herbicide, but is quite silent on the usability of the compounds as medicines.
Japanese patent laid-open No. 150,290/1988 also discloses derivatives having a heterocyclic aryl ring composed of five atoms and Japanese patent laid-open No. 210,033/1986 discloses derivatives having a nitrogen-containing heterocyclic aromatic ring composed of six atoms. These Japanese patent gazettes mention that these compounds have a bone resorption inhibitory effect. However, no compound who's hetero ring is a saturated hetero ring has been reported.
Another type of substituted aminomethylenebis(phosphonic acid) derivatives having a cycloaliphatic hydrocarbon group is also known. Japanese patent laid-open No. 37,829/1979 discloses compounds having an unsubstituted cyclopentyl group or a cyclohexyl group as the cycloaliphatic hydrocarbon group and Japanese patent publication No. 12319/1980 also discloses compounds having a cyclohexyl group as the cycloaliphatic hydrocarbon group. These Japanese patent gazettes mention that these compounds can be used as agricultural chemicals, especially as herbicide and that they can be used in a method for preventing precipitation in water or in aqueous solution, but are quite silent on the usability of the compounds as medicines.
However, such compounds that have a bicycloheptyl group, a bicycloheptenyl group or a cycloalkenyl group as the cycloaliphatic hydrocarbone group are not known.